Scientists say a massive ice sheet in Antarctica is starting to collapse. It's not going to slide into the ocean over night, but rather over centuries. Still, it will fall, scientists say. It's gotten to the point it can't be stopped — and that means rising sea levels.

Scientists say a massive ice sheet in Antarctica is starting to collapse. It's not going to slide into the ocean over night, but rather over centuries. Still, it will fall, scientists say. It's gotten to the point it can't be stopped — and that means rising sea levels.

Scientists say a massive ice sheet in Antarctica is starting to collapse. It's not going to slide into the ocean over night, but rather over centuries. Still, it will fall, scientists say. It's gotten to the point it can't be stopped — and that means rising sea levels.